Device for sharpening rock drills



Oct. 20, 1931. B. s. VETTER 1,828,580

DEVICE FOR SHARPENING ROCK DRILL| S Filed July 3. 1929 (I W wfla gm INVENTOR.

.Brady ,5. Vetter,

- w BY .9- 5 ATTO EY.

Patented Get. 20, 1931 ATES BRADY S. VETTEB, F IVIOOREFIELD, WEST VIRGINIA rricn- PATENT V nEvIoEron snnnrnivrne noon nRILIis' Application filed July 3, 1929. Serial No. 375,868.

This invention relates to a device for sharpening rook drills, and it has for its object to provide an improved article of this nature, constructed in such manner that the operation of sharpening the drills, or of forming the usual collars thereon, may be carried out rapidly and economically by hand, and without the employment of complicated apparatus.

I am aware of the fact that many patents have been granted for machines for sharpening rock drills. Many of the structures have proposed that a backing-up block be brought against the rear end of the drill to resist the pressure and blows imparted to the cutting end of the drill during the resharpening.

operation. While such an arrangement works satisfactorily,.it is impractical from r the standpoint of economy. Drillsare made in so many different sizes that the necessity of continually adjusting the backing block, and the relatively exact positioning of the same required, renders the method described so slow as toincrease the cost beyond reason. Other machines proposed have relied upon gripping devices for gripping the stock. WVhere these gripping devices are disposed at such a point as to grip the hot metal of the steel or drill sh ank, the pressure of the gripping device merely compresses the hotmetal, or sizes it downin such a way that the pressure on. the cutting end of the drill forces the drill rearwardly through the gripping device. These difficulties are obviated by means of the machine of my invention, a detailed description of which follows: I In the accompanyingdrawings: Fig. 1 is aplan view, Fig. 2 a front end view, 1 Fig. 3 a side view, partly broken away, Fig. l a horizontal sectional view, and

5 is a detail view of a collar forming tool hereinafter described.

The device of the present invention comprises a base 5, in which there is pivotally mounted the lower ends of two pairs of gripping blocks. One pair of gripping blocks comprises the two upstanding members 6-6 while the other comprises the. upstanding members 7-7 thesemembers being pivoted to downturned lugs 8 (only one of which is shown) of the base. The members constituting the gripping locks are made of such thickness and strength that they are very rigid. The hand operated toggle mechanisms comprising links 9 and 10, serve to draw the tops of the blocks 6-6 and 77 toward each other. The links 9 are joined to form, operatinghandles 11, and are pivoted to the blocks 6" while the links 10 are pivoted at one end to thelinks 9, as indicated at 11, and are pivoted at 12, to the upper portions of the blocks 6 and 7. The lower portions of the gripping blocks are channeled at 12 for the reception'of tw0-part bushings- 13-14. The bushing18is provided with a head 15, said head being provided with a taperedrecess 16, which receives a corre spondingly shaped end 17, of a die or'dolly i 18. This dolly is mounted to slide through a suitable very rigid bearing 19, and this bearing, in turn, issuppo'rted upon the base 5. The inner end of the dolly is shaped at 19 to conform to the shape of the cutting end of the drill 20. This drillis of a conventional type, and is provided with collar 23, adjacent its end, remote from its cutting end, said col- .lar coacting with the usual pneumatiohammers or drills with Which'these drill bits are used.

In using thedevice to sharpen a drill the steel or drill shank is disposed in the bushings 13- and 1 1, and these bushings, in turn, are gripped forcibly in the gripping blocks 66 and 7-7, respectively. Since the levers 9 and 10 constitute a toggle mechanism, and since this toggle mechanism, in turn, operates upon the relatively long leversprovided by the blocks 66- and 7-7 it fol lows thatthe bushings grip the steel, with a very great degree of force. I contemplate knurling the inner faces of these bushings in order to increase the gripping effect, and I may make the bushing 14 to taper slightly, I as indicated, so that rearward thrust of the drill will tend to cause these bushings to tighten down. The sharpening and shaping of the cutting end of the drill s effected by striking sharply upon the exposed end of the dolly with a sledge hammer, thereby thrusting the cutting edge of the dolly forcibly against the teeth of the drill.

The bearing 19 receives either the dolly 18 or a cap 22, said cap being used in the formation of the collars 23, upon the drill. shanks. Then a collar is to be formed, the steel or tool is reversed, so that its collar carrying end is toward the bearing 19. The sleeve 22 is then disposed in said bearing in place of the dolly, and is struck upon forcibly with the sledge in the manner previously described, with respectto the dolly. At this time, the bushing 13 is reversed, so that its plain end 13 is disposed toward cap 22. It will be understood that that portion of the tool that is gripped in bushing 13 is highly heated, while that portion of the tool that is gripped in bushing leis relatively cold. Therefore, the gripping action cannot readily size down the cold portion of the steel, as would be the case ifthe steel were heated throughout its length. Thus, it will be seen that I have two very powerful gripping devices; one of which grips and supports the steel at its hot portion, while the other grips and supports the steel at its cold portion. By virtue of this arrangement, I am able to suitably support the rod that is to be treated, against the action of the dolly 18, without the necessity of providing a stop block for the rear end of the steel. Consequently, drills of widely varying length may be quickly clamped in operative position and sharpened with a minimum of labor, and in a very short time. When the collar 23 is to be formed on the tool, the tool is reversed, so that its end remote from the drill teeth, is presented toward guide 14. At this time, the bushing 13 is reversed, so that its headed portion lies to the right hand side of the block 6-6". The cap 22 is substituted for the dolly 18 in the guide 19, and its recess 22 fits over the end of the shank of the drill. VVith the drill in a highly heated condition and clamped forcibly in bushing 13, the rod may be upset and an enlargement or collar 23 formed thereon by driving the guide 22 forcibly through the guide and upon the end of the rod.

By providing the two-part bushings as the elements which actually contact with and grip the steel, I am able to handle stock of widely varying sizes and shapes, it being only necessary to substitute appropriately sized and shaped bushings for those previously employed, in order to accommodate any change in the cross-sectional area or shape of the stock being handled. Consequently, I am able torapidly and economically handle a wide variety of drills, of different lengths, shapes and sizes.

Further, it will be observed that the mechanism employed is hand operated throughout, requiring no expensive machine work,

but consisting, in the main, of a system of levers having their action so compounded that one man may grip the stock with sufficient force to hold it against the action of the dolly or the cap, as the case may be.

It will, of course, be understood that dollies of varying shapes and cutting contour will be employed to take care of the different sizes and shapes of drills being operated upon.

It is to be understood that the invention is not limited to the precise construction set forth, but that it includes within its purview whatever changes fairly come within either the terms or the spirit of the appended claims.

Having described my invention, what I claim is:

1. A device of the character described, comprising a pair of gripping members adapted to grip a drill shank and disposed in such spaced relation with respect to each other that one of said gripping elements grips the hot portion of the shank while the other grips the cold portion of the shank, a guide and a dolly movable through said guide toward the drill held by said clamps.

2. A device of the character described, comprising a. base and a pair of gripping elements carried by said base, and spaced a material distance from each other, along said base, each of which comprises a pair of elongated stiff clamping blocks, a toggle mechanism connected to the upper ones of said blocks for drawing them toward each other, said blocks being provided with complementally recessed portions adjacent their inner ends, and split bushings in said recessed portions.

3. A device of the character described, comprising a base and a pairof gripping members carried by said base, and spaced a material distance from each other, along said base, each of which comprises a pair of coacting upstanding, elongated, rigid blocks, manually operable toggle mechanism connected to the upper ends of said blocks for drawing the blocks of each pair forcibly toward each other, the blocks of the pairs being complementally recessed along their confronting faces at a point adjacent the inner end thereof, and split bushings in said recessed portions, one of which is provided with a head lying outwardly ofsaid blocks.

1. A device of the character described, comprising a base and a pair of gripping members carried by said base, and spaced a material distance from each other, along said base, each of which comprises a pair of coacting upstanding, elongated, rigid blocks, manually operable toggle mechanism connected to the upper ends of said blocks for drawing the blocks of each p air forcibly toward each other, the blocks of the pairs being complementally recessed along their confronting faces at a point adjacent the inner end thereof, and split bushings in said recessed portions, one of which is provided with a head lying outwardly of said blocks, and the other of which is ta pered in the direction of thrust.

5. A device of the character described, comprising a base and a pair of gripping members carried by said base, and spaced a material distance from each other, along said base, each of which comprises a pair of coactingupstanding, elongated, rigid blocks, manually operable toggle mechanism connected to the upper ends of said blocks for drawing the blocks of each pair forcibly toward each other, the blocks of the pairs being complementally recessed along their confronting faces at a point adjacent the inner end thereof, and split bushings in said recessed portions, one of which is provided with a head lying outwardly of said blocks, a bearing outwardly of said blocks and having a bore in alignment with the bores of said bushings, and a dolly movable through said bearing and adapted to be driven toward stock held in said bushings.

6. A device of the character described, comprising an elongated horizontal base, and a pair of gripping members carriedb-y said base and spaced from each other to such an extent along said base as to respectively grip the hot and cold portions of a drill, each of said gripping members comprising a pair of co-acting upstanding, elongated, rigid blocks, manually operable toggle mechanism connected to the upper ends of said block for drawing the blocks of each pair forcibly toward each other, the blocks of the pairs being complementally recessed along their con fronting faces at a point much closer to the lower ends thereof than to their up er ends, and split bushings seated in said recessed portions.

In testimony whereof I aflix my signature.

BRADY S. VETTER. 

